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Sealevelgate

Filed under: — stefan @ 11 March 2010 - (Italian)

Imagine this. In its latest report, the IPCC has predicted up to 3 meters of sea level rise by the end of this century. But “climate sceptics” websites were quick to reveal a few problems (or “tricks”, as they called it).

First, although the temperature scenarios of IPCC project a maximum warming of 6.4 ºC (Table SPM3), the upper limit of sea level rise has been computed assuming a warming of 7.6 ºC. Second, the IPCC chose to compute sea level rise up to the year 2105 rather than 2100 – just to add that extra bit of alarmism. Worse, the IPCC report shows that over the past 40 years, sea level has in fact risen 50% less than predicted by its models – yet these same models are used uncorrected to predict the future! And finally, the future projections assume a massive ice sheet decay which is rather at odds with past ice sheet behaviour.

Some scientists within IPCC warned early that all this could lead to a credibility problem, but the IPCC decided to go ahead anyway.

Now, the blogosphere and their great media amplifiers are up in arms. Heads must roll!

Unthinkable? Indeed. I am convinced that IPCC would never have done this.


The North Sea (see Stefan’s photostream on Flickr)

But here is what actually did happen.

In its latest report, the IPCC has predicted up to 59 cm of sea level rise by the end of this century. But realclimate soon revealed a few problems.

First, although the temperature scenarios of IPCC project a maximum warming of 6.4 ºC (Table SPM3), the upper limit of sea level rise has been computed for a warming of only 5.2 ºC – which reduced the estimate by about 15 cm. Second, the IPCC chose to compute sea level rise up to the year 2095 rather than 2100 – just to cut off another 5 cm. Worse, the IPCC report shows that over the past 40 years, sea level has in fact risen 50% more than predicted by its models – yet these same models are used uncorrected to predict the future! And finally, the future projections assume that the Antarctic ice sheet gains mass, thus lowering sea level, rather at odds with past ice sheet behaviour.**

Some scientists within IPCC warned early that all this could lead to a credibility problem, but the IPCC decided to go ahead anyway.

Nobody cared about this.

I mention this because there is a lesson in it. IPCC would never have published an implausibly high 3 meter upper limit like this, but it did not hesitate with the implausibly low 59 cm. That is because within the IPCC culture, being “alarmist” is bad and being “conservative” (i.e. underestimating the potential severity of things) is good.

Note that this culture is the opposite of “erring on the safe side” (assuming it is better to have overestimated the problem and made the transition to a low-carbon society a little earlier than needed, rather than to have underestimated it and sunk coastal cities and entire island nations). Just to avoid any misunderstandings here: I am squarely against exaggerating climate change to “err on the safe side”. I am deeply convinced that scientists must avoid erring on any side, they must always give the most balanced assessment they are capable of (and that is why I have often spoken up against “alarmist” exaggeration of climate science, see e.g. here and here).

Why do I find this IPCC problem far worse than the Himalaya error? Because it is not a slip-up by a Working Group 2 author who failed to properly follow procedures and cited an unreliable source. Rather, this is the result of intensive deliberations by Working Group 1 climate experts. Unlike the Himalaya mistake, this is one of the central predictions of IPCC, prominently discussed in the Summary for Policy Makers. What went wrong in this case needs to be carefully looked at when considering future improvements to the IPCC process.

And let’s see whether we learn another lesson here, this time about society and the media. Will this evidence for an underestimation of the climate problem by IPCC, presented by an IPCC lead author who studies sea level, be just as widely reported and discussed as, say, faulty claims by a blogger about “Amazongate”?

p.s. Recent sea level results. A number of broadly based assessments have appeared since the last IPCC report, which all conclude that global sea level rise by the year 2100 could exceed one meter: The assessment of the Dutch Delta Commission, the Synthesis Report of the Copenhagen Climate Congress, the Copenhagen Diagnosis report as well as the SCAR report on Antarctic Climate Change. This is also the conclusion of a number of recent peer-reviewed papers: Rahmstorf 2007, Horton et al. 2008, Pfeffer et al. 2008, Grinsted et al. 2009, Vermeer and Rahmstorf 2009, Jevrejeva et al. 2010 (in press with GRL). The notable exception – Siddall et al. 2009 – was withdrawn by its authors after we revealed numerical errors on Realclimate. This is a good example of self-correction in science (in stark contrast with the climate sceptics’ practice of endlessly perpetuating false information). Rather bizarrely, Fox News managed to turn this into the headline “More Questions About Validity of Global Warming Theory“.

** About the numbers stated above. Regarding the actual IPCC AR4 numbers, adjust the IPCC upper estimate of 59 cm by adding 15 cm to make it apply to 6.4 ºC warming (not just 5.2 ºC) and 5 cm to make it go up to 2100 (not just 2095). That gives you 79 cm. Add 50% to adjust for the underestimation of past sea level rise and you get 119 cm.
For the hypothetical case at the start of this post, just introduce similar errors in the other direction. Let’s add 31 cm by going up to 7.6 ºC and the year 2105 (in fact that is “conservative” but it gives a nice round number, 150 cm). Now assume you have a model compared to which actual sea level is rising 50% slower (rather 50% faster): now you’re at the 3 meters mentioned above. For details, see The IPCC sea level numbers.


305 Responses to “Sealevelgate”

  1. 201
    Pagodroma says:

    RE 185: I also happen to live in Sweden and while post-glacial rebound is clearly still strong in northern Sweden, it is essentially zero in the southern part. Thus, rising sea levels will definitively be a problem also in our country. Also, I have my own 45 year anecdotal record of sea level at my summer house, where beach erosion is a very real problem

  2. 202
    Steve Missal says:

    Interesting statistic just out: China’s oil consumption is 28% greater than at the same time last year. This is a startling rise. I’d be very curious to see the same info from India. Perhaps it won’t take as long as we thought for the ‘upping’ of fossil fuel consumption.

  3. 203
    Edward Greisch says:

    174 Response stefan: Where will we see the engineering part? Will it be in another blog or a new part of RC?

  4. 204
    Gerry Quinn says:

    Re: #170, 172, regarding the timing of sea level rise and accelerations thereof:

    Much is being made by Stefan and a poster called Didactylos about the title of Church and White’s paper referring to acceleration during the twentieth century. Church and White themselves observe that the data appears to have a clear change in slope somewhere around 1930. They found that two linear regressions (splitting at 1935, half-way through their dataset) actually fit the sea level data *better* than their quadratic.

    “The rms residual to the linear fits is lower at 5.8mm (cf 7.5mm) consistent with much of the acceleration occurring in the first half of the 20th century rather than a smooth acceleration over the whole period” [Church and White] (The 7.5 mm refers to the rms for their quadratic fit.)

    In my original post I referred to the data I was familiar with, that of Douglas, as given in Wikipedia under ‘Current sea level rise’, and widely cited in the literature. The curve is much the same anyway, i.e. it is linear from 1930 to the present date. I would not disagree with 1930 as a break point, although one could arguably place it earlier.

    Either way, the best-fitting model of Church and White indicates that sea level has been rising at a constant rate for at least 80 years, which is pretty much what I posted initially in #119.

    So I ask once again: where does this leave Stefan’s contention in #1 that “data of the past century show how the rate of sea level rise increases in proportion with temperature”. Has temperature been approximately constant since 1930? Because, quite clearly, annual sea level rise has! I would appreciate if future responses addressed temperature and sea level data, rather than titles of reports, or ad hominems a la Didactylos.

    [Response: Did I mention that if you want to know how we got our results, it is an option to read our papers (freely accessible, linked above in the post)? They deal in sea level and temperature data and the connection between the two in some detail. -stefan]

  5. 205
    Completely Fed Up says:

    “202
    Steve Missal says:
    14 March 2010 at 5:41 PM

    Interesting statistic just out: China’s oil consumption is 28% greater than at the same time last year. This is a startling rise. I’d be very curious to see the same info from India.”

    How about the US? I’d be interested in that.

  6. 206
    Elmar Veerman says:

    I hope mr Robbert Dijkgraaf will read this post.

  7. 207
    J says:

    IEA: “But the agency said that demand in the area covered by the Organization for Economic Cooperation and Development remained “persistently weak” and would fall by 0.3 per cent this year.”

    “The OECD group’s 30 developed economies including Britain, France, Germany, Japan and the U.S., which account for most of global economic output.

    “This year’s global oildemand growth will be driven entirely by non-OECD countries, with non-OECD Asia alone representing over half of total growth,” it said.”

  8. 208
    flxible says:

    CFU@205

    U.S. Liquid Fuels Consumption. U.S. liquid fuels consumption declined by 810,000 bbl/d (4.2 percent) to 18.7 million bbl/d in 2009, the fourth consecutive annual decline. Motor gasoline was the only major petroleum product whose annual consumption did not decline. Distillate fuel consumption declined by 310,000 bbl/d (8.0 percent) in 2009, led by a sharp economy-related decline in transportation usage.

    The economic recovery contributes to projected growth in total liquid fuels consumption of 200,000 bbl/d in 2010 and 210,000 bbl/d in 2011. Nevertheless, expected U.S. consumption in 2011 is lower than total consumption was in 1999 and is 1.7 million bbl/d lower than the highest level of annual consumption reached in 2005.

    from here

    & Steve@202
    Isn’t per capita use more relevant? [~2008 ranks]:
    # 1 Virgin Islands: 845 bbl/day per 1,000
    # 10 Saudi Arabia: 83 bbl/day per 1,000
    # 19 Canada: 71 bbl/day per 1,000
    # 23 United States: 68.6 bbl/day per 1,000
    # 62 United Kingdom: 29 bbl/day per 1,000
    # 144 China: 5.7 bbl/day per 1,000
    # 165 India: 2.4 bbl/day per 1,000

  9. 209
    Completely Fed Up says:

    flxible, maybe Gilles will use that as proof that CO2 is the lifeblood of economic recovery, then…!

  10. 210
    J says:

    Yes, energy usage and economic activity vary proportionately.

  11. 211
    Tgorle says:

    There’s always lots of good information being exchanged here at Realclimate, which is why I continuously come to the site. The criticism of the IPCC, however, is unfounded.
    The IPCC is not narrow-minded, nor are they politically motivated or getting big grant dollars from whomever. It represents a collaborative of respected scientists from across the world, from numerous countries and biomes, with, I’m sure, unique concerns for their home nations.
    This is good. It ensures that no one personal bias dominates their studies, and that all views get consideration. What some people don’t like to hear is that all views basically agree that human activity is altering the climate, making it warmer, and that there is a positive feedback.
    Aye, there’s the rub. Positive feedback. Permafrost defrosting, methane emission, loss of the ocean’s ability to sequester carbon. Not to mention thermal expansion and inundation of low-lying areas, which creates marshes and swamps- which in turn release more methane and CO2.
    All this while the human population is expected to keep ballooning. Has the IPCC taken this into account? absolutely. If different areas of the scientific community- biologists, geologists, meterologists, etc. each do their own studies, based only on information from their field, there will be different results. Only the IPCC addresses information gathered from across the scientific spectrum, and with that, they have added credibility.

  12. 212
    Dave Burton says:

    Didactylos wrote on 14 March 2010 at 8:41 AM:
    > …you stoop to that most contemptible trick of graphing fraudsters: expand
    > the Y axis enough, and magically any trend will disappear. “Look! It’s
    > flat!” you cry. Well, of course it is. You scaled the data inappropriately.
    > When you are interested in mm/year, a Y axis scaled in metres is a pretty
    > big clue that you are Doing It Wrong.

    Dear Didactylos,

    I assume that you are complaining about these graphs, to which I linked in my previous message:

    Warnemunde, Germany:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=120-012

    Copenhagen, Denmark:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=130-021

    Sydney, Australia:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=680-140

    (You can find links to the other 156 GLOSS-LTT tide station LMLS graphs here: http://www.burtonsys.com/climate/MSL_global_trendtable1.html )

    Didactylos, may I suggest that you direct your criticism of the graphs to the good folks at NOAA. The graphs are theirs, not mine, as you can see from the URLs. At the bottom of each graph page is a link to NOAA’s contact information:
    http://tidesandcurrents.noaa.gov/contact.html

    For the record, I think NOAA a good job on this. The Local MSL trend analyses and graphs appears to be carefully and competently done. But if you disagree, please take it up with them, not me.

    The fact is that the longest and best quality tide gauge records of local mean sea level graph out as essentially straight lines + noise. They show that the global average MSL trend has been steady at less than 1.2 mm/year for at least 120 years, with no sign of acceleration in 1910 or 1925 or 1985 (Fu) or 1993 (IPCC) or any other date.

    Didactylos also wrote:
    > You also complain about cherrypicking end-points! Given that the conclusion is not dependant
    > on endpoints, but is merely an illustration of the acceleration, your complaints are
    > completely spurious.

    Wrong. I am disturbed that you dismiss fraud as “merely an illustration,” as if it were harmless. The fact is that the conclusions (the 2.0 and 3.2 mm/yr slopes of the lines) obviously ARE dependent on the cherry-picked endpoints.

    The fact is that the longest and most reliable tide station local mean sea level measurement records graph as essentially straight lines + noise. They show that there has been NO measurable acceleration in mean sea level rise on the world’s coasts since the mid-to-late 1800s.

    Didactylos also wrote:
    > When it comes to concrete evidence, you suddenly decide to cherry pick yourself – not an
    > endpoint, but singling out individual tide records, in the vain hope that we would forget
    > about the rest.

    Wrong. I gave you links to the graphs of ALL the GLOSS-LTT tide station records, and I challenged you to “find even one which shows” Fu’s claimed uptick in rate of MSL rise.

    I wrote, “don’t take my word for it, see for yourself. Go to the spreadsheet:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html
    …look at the 44 GLOSS-LTT tide stations which have been in operation since the 1800s. Click on the tide station names to view the graph (at noaa.gov) of Local Mean Sea Level at that tide station.”

    (Did you notice that I wrote “at noaa.gov?” I really wish you guys would bother to READ before you criticize!)

    Hank Roberts wrote on 14 March 2010:
    > Insist the old data is the most reliable while ignoring new work?
    > The old data is known inadequate to show sea level change, according to the references I find.

    At issue is whether there has been any acceleration in the rate of Mean Sea Level rise since the late 1800s. I’ve seen claims of accelerations occurring at about 1910, 1925, 1985, and 1993.

    None of those dates are recent, which is why we have to rely on old data.

    Fortunately, we have actual measurements of sea level at coastal tide stations from back then. Yes that data is “old,” but it is the only reliable data we have, and it is unquestionably more reliable than computer modeling results, where the models are modeling processes that aren’t well understood.

    Andrew Hobbs wrote on 13 March 2010 to Septic Matthew:
    > simple averaging of raw culled station data as used by Dave Burton is not appropriate.

    Andrew, I obviously did not do just “simple averaging of raw culled station data.”

    For the second time I ask you, please do me the courtesy of READING it before criticizing it. Here’s the link:
    http://www.burtonsys.com/global_msl_trend_analysis.html

    Andrew Hobbs wrote on 13 March 2010:
    > The only acceptable process is to go through each and every station and find out
    > using knowledge and data independent of the sea level data, whether there are
    > any anomolies associated with that station. … or even whether tidal stations
    > have been moved etc.

    If you look at the data, Andrew, you will see that NOAA has already done this. See, for example, the graph for Goteborg, Sweden:
    http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=050-032

    Note how NOAA handled the discontinuity in 1969, when the station was relocated.

    Andrew also wrote:
    > Glacial Isostatic Adjustment would be the major effect

    We can only RELIABLY correct for things that we can measure. We have no historical measurements of glacial rebound or subsidence due to groundwater pumping, so adding dubious fudge factors based on questionable computer models just corrupts the data.

    What we do have, fortunately, is long running reliable measurements of sea level at locations unaffected by glacial rebound. Nearly all of them show the same thing: a straight line (plus noise), with no sustained acceleration in the rate of MSL rise at all since at least the late 1800s.

    Andrew wrote:
    > All you did was to look at a few of the records; no analysis in any way.

    If you’d actually READ it you’d know that’s nonsense.

    I’ve personally looked at all 159 of the GLOSS-LTT tide station MSL graphs. I found just ONE station (with a much shorter than typical LMSL record) which seems to show an uptick around 1975 (but no subsequent increase). I found one other (with rough, sporadic data), where there was a large nearby earthquake in 1993, which hints at a coincident uptick. Also, Brest & Aberdeen (two of the longest records) show slight upticks in the late 1800s.

    But the great, great majority of tide gauge locations have recorded NO sustained increase in MSL trend, ever. See for yourself:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html
    (click on the location names to see NOAA’s graphs)

    If you look at the MSL graphs for the longest and most reliable tide gauge records, you cannot fail to notice that, even as CO2 emissions have soared, there has been no corresponding acceleration in MSL trend since the late 19th century — in direct contradiction of the IPCC’s claim that “coastal tide gauge measurements confirm” an accelerating rate MSL rise.

    All my code and data is available for download, along with simple instructions to make it easy for you to duplicate and verify the results:
    http://www.burtonsys.com/climate/whatif.html

    Andrew, you wrote, “you did… no analysis in any way” even after I’d already given you access to the code and spreadsheets which show how I analyzed the data! How can you just write nonsense like that when even a cursory skim of the material would tell you that it was nonsense??

    Here’s a brief summary of what I did to analyze the GLOSS-LTT tide station data:

    First, of course, I calculated the simple average. It is only about 0.6 mm/year, which is 1/3 of the IPCC’s claimed rate.

    Then I calculated the median. It is only about 1.1 mm/year — still less than 2/3 the IPCC’s claimed rate.

    So then I calculated a time-weighted average. In other words, suppose that, instead of weighting each tide station equally, we weight each tide station-year equally. That means we weight a tide station which was in operation for 100 years with twice the weight of a tide station that was in operation for just 50 years.

    Calculated that way, the average is just 0.5 mm/year.

    Next, I weighted the observations according to their distances from other stations, so that areas with larger numbers of stations would not over-influence the calculated global average.

    Note that Church & White (2006) apparently made some attempt at this. They wrote, “Where there are multiple records near a single satellite grid point, the changes in height at each time step were averaged.” But they gave no details of how this was done or what they considered “near.”

    To know what SHOULD be considered “near” it is necessary to know something about the granularity of the local effects which affect local mean sea level. First, I had to find the latitude/longitude data for all the GLOSS-LTT tide stations (which NOAA doesn’t list). Then I wrote a program to calculate the distances between tide stations, from their latitudes & longitudes. Then I analyzed the correlations between sea level trends and geographical distances between tide stations.

    I found that beyond a distance of about 800 km there is no discernable correlation, beyond about 400 km the correlation is slight, and below 400 km the correlation is approximately linear, approaching 1.0 at short distances.

    The distance-based weighting is based on a piecewise-linear approximation of the observed correlation. vs. distance.

    The distance-weighted average mean sea level trend turned out to be about the same as the median: 1.1 mm/year.

    I also combined the distance-weighted averaging with time-weighted averaging. The result was 1.1 mm/year.

    I also repeated the calculations after discarding varying numbers of outliers (the stations with the highest and lowest sea level trends). Every result was between 0.4 mm/year and 1.2 mm/year, and the distance-weighted averages were all between about 0.9 mm/year and 1.2 mm/year.

    I even tested a very broad range of different distance-weighting functions. The results varied from 0.6 mm/year to 1.2 mm/year, with all the reasonable and semi-reasonable weighting functions resulting in about 1.1 mm/year.

    Note that the code to enable you to easily reproduce all these calculations is all available for download on my web site. It has been tested under both Linux and Windows.

    The bottom line is that there simply is no avoiding the conclusion that the IPCC’s claimed 1.7 or 1.8 mm/year rate of MSL increase exaggerates the true global average rate of sea level increase by at least 50%.

  13. 213
    Completely Fed Up says:

    “Yes, energy usage and economic activity vary proportionately.”

    Really?

    So Virgin Islands is the most prosperous country in the world?

    Cool.

  14. 214
    J says:

    Malthus would not have predicted the decline in birth rates in the developed countries either.

  15. 215
    Completely Fed Up says:

    “Didactylos, may I suggest that you direct your criticism of the graphs to the good folks at NOAA.”

    If that were so, why did you not use their graph in your paper? Why did you go and use your own graphing?

    The NOAA graph shows a trend. You take the data and throw it about until it looks a mess and they proclaim that the data doesn’t show anything because it’s a mess.

  16. 216
    J says:

    >>>>”So Virgin Islands is the most prosperous country in the world?”

    Perhaps they’re on the leading edge of figuring out how to increase economic activity dramatically without energy.

    Or perhaps that’s just silly.

  17. 217
    Dave Burton says:

    Completely Fed Up wrote on 15 March 2010:

    >> “Didactylos, may I suggest that you direct your criticism of the graphs
    >> to the good folks at NOAA.”
    >
    > If that were so, why did you not use their graph in your paper? Why did
    > you go and use your own graphing?
    >
    > The NOAA graph shows a trend. You take the data and throw it about until
    > it looks a mess and they proclaim that the data doesn’t show anything
    > because it’s a mess.

    I have no idea what you’re talking about. I used NOAA’s graphs exclusively for the LMSL trends. The graphs I made were for things NOAA didn’t graph.

    I don’t know what “throw it about” means, either, but I certainly didn’t “proclaim that the data doesn’t show anything because it’s a mess.”

    Rather, what the data does very clearly DOES show is that global average mean sea level has been rising at less than 1.2 mm/year since the 1800’s, and shows no sign of accelerating.

    If there’s something you don’t understand, then just ask, and I’ll try to explain or clarify it.

    Dave Burton
    Cary, NC

  18. 218
    Hank Roberts says:

    > Virgin Islands
    > energy use per capita

    Something grossly skews that — I vaguely recall this from something I read years ago.

    I think it’s so high because the Virgin Islands is the place a great many ocean shipping companies register their vessels, a “flag of convenience — so all the fuel consumed by their business is credited to the Virgin Islands (although the ships never stop there, and neither does the income from burning the fuel).

    It’s another argument for tracking carbon benefits, not just carbon burned.

  19. 219
    Septic Matthew says:

    208, flxible: Isn’t per capita use more relevant? [~2008 ranks]:

    Relevant to what? Certainly Americans can cut petroleum use with little effect on total health and wealth, but the Chinese govt. will from now on dominate the international government-level discussions of policy, such as, What to do about AGW? What to do about Darfur? What to do about Iran? In discussions of civil liberties in Saudi Arabia, the US never had much influence, and now has none; Saudis will go to college in China, and buy their flying toys from China.

  20. 220
    Didactylos says:

    Sorry, Dave Burton. Further study of your site reveals you as a crank, and I know better than to waste time with cranks.

    I find it amusing, though, how you simply repeat yourself (using twice as many words) when any error is pointed out to you. Saying things all over again doesn’t add any weight to your argument, it just makes us conclude that you failed to understand the criticism.

    I do apologise for assuming you had generated the graphs yourself. Instead, you just rescaled them so that the trend is very difficult to see.

    And with that, we must say goodbye.

  21. 221
    flxible says:

    Matthew – Relevent to the previous poster that reported that Chinese petro use had increased 28% …. not sure what the Saudis education has to do with the climate, but your apparent concern over the growing Chinese influence on the shape of your future is interesting – aren’t the Chinese also increasing non-fossil energy use rapidly?

    Hank@218 – Someone must stop there, because the US Virgins import AND export very large volumes of oil, producing none and using no other form of energy domestically.

  22. 222
    GlenFergus says:

    #212 Dave Burton:

    Congratulations for actually doing the work, unlike many. You might even have spotted something important (the correlation distance; do you know some geostatistics?). But you’ll need to watch those sweeping statements (and confirmation bias?) if you want to be taken seriously.

    The bottom line is that there simply is no avoiding the conclusion that the IPCC’s claimed 1.7 or 1.8 mm/year rate of MSL increase exaggerates the true global average rate of sea level increase by at least 50%.

    No. What you actually found is that IPCC’s rate is inconsistent with your average of the NOAA tide gauge data. You found nothing about its consistency or otherwise with a “true global average”, which tide gauges cannot measure. (That is without model-based interpretation, which you disdain … rather foolishly, I think.)

    And on your website:

    The IPCC’s claim that “coastal tide gauge measurements confirm” an accelerating rate of MSL rise is nonsense.

    Yes, you did find that; possibly correctly. But “nonsense” seems unnecessarily loaded.

    The obvious conclusion is that anthropogenic CO2 does not appear to cause a significant increase in sea level.

    Sweeping, unsupported and absurd. This greatly weakens your whole effort.

  23. 223
    Mark A. York says:

    Really Dave, anyone who couches criticism with this red flag: “How did the IPCC’s AGW alarmists get it so wildly wrong?”

    is not the sort of scientist where new revelations in science come from.

  24. 224
    Frank Giger says:

    From Flxable:

    “Isn’t per capita use [of fossil fuels] more relevant?”

    Absolutely not!

    This is the worst sort of statistical mumbo-jumbo one can come up with in regards to climate change. The atmosphere and oceans do not care one whit about per capita additions of GHG’s – they only respond to totals.

    If one person (group A) pours a ten gallon bucket of oil in a pond: per capita is ten gallons, total of ten gallons.

    If ten people (group B) each pour one gallon of oil into it: per capita is one gallon of oil, total of ten gallons.

    Hurray for group B! Or, maybe not. The pond isn’t effected by how many people put the ten gallons of oil in it, only the total.

    Now we can make this even more insidious, once we’ve established that per capita is the norm of measurement. Let’s get group C, which has 100 people in it. They pour only one half of a gallon of oil into the pond per person, making them much less polluting than either group A or B usign the per capita measurement.

    Except it’s 50 gallons in total.

    Who’s the worst polluter?

  25. 225
    Gilles says:

    “Response: What is your argument: that 10 meter rise is not worse than 3 meter rise, because in either case we are “doomed”? That may be true if you live on the Maldives, but not in most other parts of the world. It would seem a rather far-fetched justification for a do-nothing attitude. -stefan”

    First I understand that you recognize I’m right (which is not obvious for all readers of this thread) : if inertia is very long, then we cannot avoid a several meters rise of the sea level, whatever we do, even if we stopped now any carbon emission. I first think that it is must be clearly stated by people like you, who understand what a relaxation time is, which may not be the case of a general audience.

    So it should be clearly understood that, if your model is right, strongly reducing the amount of carbon we burn would NOT avoid a 10 meter rise, it would just limit it to 10 meters instead 20 or 30 meters. Now much obviously with a 10 meter rise there will be in any case a considerable change on coast lines and we’ll have to move anyway billions and people and hundred of cities. So one could really ask : since we have to move anyway, is it better to keep fossil fuels to do the move and go simply higher and farther in the land, or to stop using them and fight water with our hands? I have no easy answer, I think the debate is interesting.

    [Response: From my 2007 paper:

    Paleoclimatic data suggest that changes
    in the final equilibrium level may be very large:
    Sea level at the Last Glacial Maximum, about
    20,000 years ago, was 120 m lower than the
    current level, whereas global mean temperature
    was 4° to 7°C lower (5, 6). Three million years
    ago, during the Pliocene, the average climate
    was about 2° to 3°C warmer and sea level was
    25 to 35 m higher (7) than today’s values. These
    data suggest changes in sea level on the order of
    10 to 30 m per °C.

    I’ve stated many times in public (eg in most of my talks and in the book “Our threatened Oceans“) that we’re heading for many meters of sea level rise in the very long run. I would not go as far as you in stating that 10 meters are inevitable, though. Mind you that is centuries down the line – after we’ve achieved the zero-emissions society later in this century, we may actually find ways to achieve significant negative emissions (eg by using bioenergy with carbon sequestration) or even geoengineering schemes to lower temperature or sea level – who knows what is possible in a hundred or two hundred years? I’d say it is unlikely that humanity will let ten meters of sea level rise happen. That is why the key issue to me is doing what our generation can do now to avoid the worst happening within this century, and then see what subsequent generations can do further. -stefan]

  26. 226
    Hunt Janin says:

    This may be a foolish question, but I’ll risk asking it anyway. If you want to reply, please do so to me directly at huntjanin@aol.com to avoid troubling the experts.

    The question is this: at what point will developed nations REALLY BE FORCED TO DO SOMETHING about sea level rise? At l.5 meters, 2 meters, 3 meters, or what? In other words, at what point will the danger of doing nothing become so great that it overcome political inertia?

    [Response: A cynic might respond: never. We’ll just switch from “not sure whether it is serious enough to do something” to “now it’s too late to do something”. -stefan]

  27. 227
    Completely Fed Up says:

    “224
    Frank Giger says:
    16 March 2010 at 12:35 AM

    From Flxable:

    “Isn’t per capita use [of fossil fuels] more relevant?”

    Absolutely not!”

    Why then do you not explain why not?

    “The atmosphere and oceans do not care one whit about per capita additions of GHG’s – they only respond to totals.”

    But the totals come more from each USian than each Chinese. Therefore the greatest “bang for the buck” comes from the US changing their use.

    The bang-for-the-buck DOES depend on per capita.

    You just don’t want to think of that. Better to leave the US ahead, yes?

    “If one person (group A) pours a ten gallon bucket of oil in a pond: per capita is ten gallons, total of ten gallons.

    If ten people (group B) each pour one gallon of oil into it: per capita is one gallon of oil, total of ten gallons.”

    But if you arrest group A you fix the problem ten times easier than if you arrest group B.

  28. 228
    Hunt Janin says:

    Thanks, Stefan.

    You may possibly remember that in the book (an introductory survey) I’m now writing on sea level rise, I want to speculate on the political, economic, military, and social effects such a rise may have in the distant future.

    I do realize that these topics are off-limits for this website but hereby invite anybody who has views on these effects to contact me directly at huntjanin@aol.com.

  29. 229
    Frank Giger says:

    Fed up, I explained why per capita is a bad measurement quite well, I thought.

    Per capita has no bearing on totals to the environment. And it is total emissions that matter.

    Arresting Group A won’t save the pond. Groups B and C will see that the fish are all dead.

    But it will fit a political agenda.

  30. 230
    wilt says:

    Stefan, thank you for your comment at my #193 post. The ‘sea level sensitivity’ that you introduce here has a value of 2.1 mm/year/degree when one uses the Church&White calculation, and 2.6 in your calculation. Now for a period of 90 years (2010-2100) this would mean for each degree of temperature rise a sea level rise of 19 or 23 cm, respectively. As you well know, the best estimates for temperature rise by 2100 in five of the six IPCC scenario’s are below or slightly above 3 degrees (the values are 1.8, 2.4, 2.4, 2.8, 3.4, 4.0). A 3 degree temperature increase by 2100 would then cause a total sea level rise of 57 cm (Church&White) or 69 cm. In this perspective, the 59 cm mentioned in the IPCC report is not implausibly low, in my opinion. Especially when you consider the trend values in temperature in the recent decades (approximately 0.16 degree per decade, by extrapolation this would yield only 1.4 degrees temperature rise by 2100).

    [Response: But now you’re comparing the upper limit of the IPCC range to a central estimate for a moderate warming, based on a quadratic sea level fit rather than on the actual correlation with temperature … what is the point? Just to justify a lower number? -stefan]

  31. 231
    Completely Fed Up says:

    “229
    Frank Giger says:
    16 March 2010 at 8:37 AM

    Fed up, I explained why per capita is a bad measurement quite well, I thought.”

    “Absolutely not” is no explanation.

    “Per capita has no bearing on totals to the environment.”

    But it has everything to do with how to solve the totals to the environment.

    In no ways is it “absolutely not!”.

  32. 232
    Ray Ladbury says:

    Frank Giger,
    I agree that simple per capita measurement can be misleading and that total emissions are what matters. However, I think that in a country with high consumption per capita has more opportunity for reduction, and if that is successful, then high-population, low per capita countries could also adopt the strategies.

    For once, people are going to have to realize that everyone’s actions matter. China’s efficiency gain is ours and vice versa. It is quite the opposite of a zero sum game.

  33. 233
    flxible says:

    Frank Giger@224 “Who’s the worst polluter?”
    The problem with your examples Frank, is that in the real world the “group oil dumped” is not equal. Fast math = the Chinese percapita [~0.006 bbls/person/day – total= ~7.5million bbls/day] would have to go up 10+ times to match that of the US [~0.07 bbls/person/day or ~21million bbls/day]. I entirely agree that the planet doesn’t care where it comes from, but your vehemence looks like the US cry “why should I cut back if they don’t”. We need to lean it out as much as possible as fast as possible, the highest percapita is where the most “fat” is, which also happens to be where the technology should be affordable and available, social circumstances do count.

    Note I was responding to the comment that China has recently had a 28% increase in oil consumption, which isn’t a good thing but, is that really more significant [0.006->0.008 or 7.5->9.5million] than say a 28% decrease in the US [0.07->0.05 or 21->15million]? We’re still dumping 10 times more into the pond. It seems to me their increase was as much due to their production of export goods as anything else – you’re right, global is global, but there are definitely some regions that can affect change faster than others and the fastest way to cut Chinas emissions is for the West to stop importing so much [disposable] production from them, meaning for the US to drastically cut consumption of all kinds.

    Also re the over the top consumption of the Virgin Islands, I haven’t explored that, but as that’s actually part of the US economy [US$ is the currency, even in the British Virgins], likely all the oil that gets imported there than moved on to elsewhere should actually be chalked up to the US [probably trans shipped to US refineries, but I think it’s being credited to “the Virgin Islands”.

  34. 234
    Nick Gotts says:

    So one could really ask : since we have to move anyway, is it better to keep fossil fuels to do the move and go simply higher and farther in the land, or to stop using them and fight water with our hands? – Gilles

    But you have been arguing that fossil fuel supplies are very limited, and industrial society is bound to collapse when they run out – so by your own logic, we should reduce their use as fast as possible so we still have some left for the big move. It is clear you will say anything that suits your argument of the moment, irrespective of whether it is consistent with what you have said before. That is a clear mark of someone who is not arguing in good faith. (And no, I have no interest in betting against someone who is clearly acting in bad faith, and does not give their full name. I leave you to guess why.)

  35. 235
    James Staples says:

    If everyone hasn’t seen it already, read the Feb. 12th Item, in Science, about the study of Calcite Formations in Mallorcan Sea-Caves.
    They have convincing proof that, at ~ 82 kya, the Seas were at least a Meter higher then, than they are now; though Atmospheric CO2 was not even close to the levels it is now.
    I’ve tried to plot the Milankovich Cycles for that date – as the Authors did not care to address the why of their findings – but I don’t have a good enough graph to plot the time period accurately enough.
    Oh! I bet Real Climate has, don’t you? I’ll look!
    BTW: I think the Toba Eruption may be responsible for the subsequent return to Ice Age Conditions, after this MIS 5a Sea Level Peak.

    [Response: What makes one local paleo data point “convincing proof” to you? -stefan]

  36. 236
    Frank Giger says:

    The truth is that the Chinese are putting more GHG’s into the atmosphere as a total than the USA is.

    Per capita matters little when one is talking about climate change threats; only the totals matter to the system.

    Similarly, growth in Chinese emissions isn’t just oil use. Like in the USA, its coal fired power plants that represent the bulk. And they’re building them like there is no tomorrow.

    That is mutually exclusive from saying the USA shouldn’t reduce emissions. There’s no whiney “but they’re doing it, too!” in pointing out the fact that per capita emissions is a false indicator of “greenish” behavior.

    Indeed, the argument has been turned on its head; those countries with high populations and emerging industrialization have used it as cover to mask total emissions for political (and financial) gain.

    The disturbing trend is that the outsourcing of emissions and pollution to the Chinese by way of manufacturing relocation from the USA is just about at the maximum level; globalization has worked in that the domestic Chinese market is now producing for its own consumers, and will increasingly do so. They’re even outsourcing their own manufacturing to Vietnam and other countries.

    On the Virgin Islands – it’s outsourcing of GHG’s by way of a humongerous oil refinery there that’s skewing the numbers. Puerto Rico, for example, gets zero GHG credit (or debit, depending on outlook) for refining crude into gasoline and diesel, since its done for them on St. Croix.

    The sad thing is we know how to do targeted, regionalized cap-and-trade; heck, we did it within the largest single CO2 emitting industry within the USA with regards to mercury and sulfur to mitigate acid rain. Even as one of those evil Republicans I can get behind making the industry responsible for some 40% of the nation’s CO2 emissions more efficient and less polluting. Bushels full of carrots by way of tax credits to go with it as well – and fat bonuses to execs be damned, what matters is cleaner (or even phased out) plants.

  37. 237
    Septic Matthew says:

    232, Ray Ladbury: China’s efficiency gain is ours and vice versa. It is quite the opposite of a zero sum game.

    That’s worth repeating and remembering. Economics is usually a positive sum game, and war is usually a negative sum game (first side to 0 loses to the side that remains positive, though there may be tremendous productivity at some points during the war, as with US, Germany and USSR in WWII.)

    China is worth thinking about in detail as they simultaneously work on: increasing CO2 output, increase CO2 sequestration, increase efficiency, and increase generation from renewable and nuclear sources.

  38. 238
    Septic Matthew says:

    221, flxible: Matthew – Relevent to the previous poster that reported that Chinese petro use had increased 28% …. not sure what the Saudis education has to do with the climate, but your apparent concern over the growing Chinese influence on the shape of your future is interesting – aren’t the Chinese also increasing non-fossil energy use rapidly?

    The bit about Saudi education is off on a tangent, but the point about diminished US influence in the oil markets is relevant to any discussion about what the US and EU might attempt to achieve by any international energy/climate/other settlements that might require Chinese cooperation.

    As to your question, the totality and complexity of current Chinese development is astonishing, and not easy to address in a few short notes. Forecasts vary, but China will probably start to reduce its CO2 emission in the era of 2030 – 2060. That’s if “the present trends” continue. And if those same “present trends” continue, China will be producing more CO2 per year by the time of the decline than the whole anthropogenic world does now.

    And ironically, the carbon-intensive industries in China have been financed in part by CO2 offsets paid by EU companies. Another irony is that 500,000 Chinese work in Africa, but they leave the local governments in power so they are not stigmatized by the label “colonists”, so no one objects.

    These considerations are far afield of the science of AGW, but once we venture into politics and policy (e.g. the Copenhagen meetings and other meetings; “risk management”) they become important.

  39. 239

    You know, I went to the Virgin Islands, but I couldn’t find any…
    Okay, I’ll shut up.

  40. 240
    J says:

    What’s the math?

    If China and India continue their CO2 growth, what percentage decrease would be required of the US to cause a valuable decrease in temps?

    Or, if the CO2 production of the US went to zero what would be the temp decrease over say 50-100 years?

  41. 241
    flxible says:

    Total CO2 emissions from China, with 5 times the population, are about 1% higher than those of the US. In order for China to decline to the global per capita level they would have to reduce by under 5% – in order for the US to decline to that same average, it will have to reduce per capita by 78%, how many are willing to do their share? [and I notice on the list that the US Virgin Islands are included in the US figure]. Denying the inordinately large contribution of the developed world to the problem is where the political and financial gain is being covered up, lets look at getting our house in order, capping and trading will only shovel more money under the CO2 blanket.

  42. 242
    David Jordan says:

    Cliff Ollier has published a strongly worded critique of the view that rapid ice-sheet movement is occuring or will occur in response to a warming climate. I have no expertise in this field, nor a strong commitment to any view here – except that good science is paramount and intemperate language (which Ollier uses) unhelpful. It is particularly striking because it is published in Geoscientist – the magazine of the Geological Society of London – and thus carries considerable weight.

    Would anyone care to comment? Yo will find the piece here http://www.geolsoc.org.uk/gsl/site/GSL/lang/en/page7209.html

    [Response: “Strongly worded critique” indeed. I would have said “Snarkily-worded diatribe”. Isn’t it obvious from the tone of the article that Chris Ollier has more words than wisdom? In any case, however much of an idiot Ollier may or may not be, his essay stands (or rather, falls) by itself.

    Here’s a typical phrase: “glaciers do not slide on their bellies, lubricated by meltwater.” Umm. No. Basal sliding is well observed phenomenon, if not completely well understood. Ollier seems to think old references carry more weight, so he might try reading Weertman, 1957, On the sliding of glaciers. Journal of Glaciology, 3(21), 33–38.

    Here’s another ‘scientific-sounding’ phrase from Ollier: “glaciers are pushed by the weight of the glacier, not sucked by the calving at the ice front.” Sounds good, doesn’t it? My response to this is F=Ma. Try reading this: Evolving Force Balance at Columbia Glacier, Alaska, During it Rapid Retreat, by S. O’Neel, W.T. Pfeffer, R.M. Krimmel, and M.F. Meier (JGR Earth Surface, Vol 110, F03012, doi:10.1029/2005JF000292, 2005), which is available on line here.

    Bottom line: Ollier’s article is complete and total B.S.

    –eric ]

  43. 243
    Completely Fed Up says:

    “It is particularly striking because it is published in Geoscientist – the magazine of the Geological Society of London – and thus carries considerable weight.”

    Geology isn’t climatology.

    Don’t assume. Check.

  44. 244
    Completely Fed Up says:

    “The truth is that the Chinese are putting more GHG’s into the atmosphere as a total than the USA is.”

    The truth is that the US can easily reduce CO2 production by 40%. China would find it much more difficult.

    The truth is that the US is the low-hanging-fruit in mitigation.

    The truth is that the US now has the opportunity of putting their money where their mouth is on their aspiration to “Leader of the Free World”.

    So Lead, already.

  45. 245
    David Jordan says:

    I’m pleased to see that the online Letters page ( http://www.geolsoc.org.uk/gsl/site/GSL/lang/en/letters ) contains two replies which take issue with Olliers’ view. But it does seem surprising that a body as significant as the GeolSoc would publish such a piece without caveats.

  46. 246
    David Jordan says:

    I’m aware that Geology isn’t Climatology, CFU, and I don’t really understand what you think I’m assuming or what I should be checking. Given that the GeolSoc is one of the principal voices of Geologists in the UK (including Quaternary Geologists who often do know something about glaciers) and that its views carry weight across the environmental sciences, I am simply expressing concern that such an article would have got through its editors.

  47. 247
    Didactylos says:

    David Jordan:

    The piece is aptly named, though. Quite how or why such nonsense got published, I cannot divine. I lost count of the times it used the term “alarmist”. No doubt they think it’s okay to publish opinion in the interest of selling more subscriptions to outraged readers…. I hope it backfires.

    “Glaciers – science and nonsense”. Lots of nonsense, very little science. I’m not an expert, and even I can detect the nonsense. Such condescending tripe about Archimedes’ principle, and that idiotic strawman about Vostok.

    Why is a soil scientist and volcanologist spouting off about glaciers, and exhibiting painful ignorance while doing so?

  48. 248
    Completely Fed Up says:

    “246
    David Jordan says:
    17 March 2010 at 9:58 AM

    I’m aware that Geology isn’t Climatology, CFU, and I don’t really understand what you think I’m assuming or what I should be checking”

    You’re positing that that discussion was in a geology journal and therefore important for climate science.

    This indicates that you consider geology to be climate science.

    You posit that just because it appears in a presigious place for geology (guess where most of the money for geology majors comes from, by the way), that this gives gravitas to the discussion.

    This indicates that you consider prestige in geology equates to prestige in climate science.

    You assert that the discussion is a killer argument.

    But that is based on your misapprehension that geology is the same as climate science.

    You didn’t check.

    [Response: Give the guy a break. He was just asking about an article. I gave him a solid and helpful answer. Can’t we leave it at that, folks?–eric]

  49. 249
    Hank Roberts says:

    Use that “edit” tool, Eric!
    http://www.cartoonstock.com/newscartoons/cartoonists/amc/lowres/amcn39l.jpg

    There are some good thoughtful letters at the geology site; one writes:

    — excerpt follows —
    As geoscientists, I think we owe it to ourselves, and to those we interact with, to be well-informed about humanity’s ability to influence the global climate. However, I suspect that many non-academic geoscientists like myself, who do not have the time or resources to read deeply into the literature, are at little advantage over journalists and others who seek to interpret climate science to the public and our elected representatives. I wish I could sustain an informed critique of those who criticise the ‘consensus’ predictions of the Intergovernmental Panel on Climate Change (IPCC) as being either exaggerated or too conservative, but I cannot (not in detail, anyway; and it’s the details that some of the ‘sceptics’ tend to focus on)…. So what is to be done?

    … I think the Geological Society should remind Fellows of their ethical duties as scientists to avoid making deliberately misleading statements about climate science (or indeed any other type of science), driven by non-scientific (e.g. political) agendas. The Society has, after all, seen it necessary to produce a Position Statement repudiating “Creation Science (attempts by Young Earth Creationists to gain acceptance for what they misrepresent in public as corroborative empirical evidence for their view)” as “a trespass upon the domain of science”. I do not think it is stretching a point to see the tactics of some seemingly scientific deniers of anthropogenic climate change as being akin to (albeit more sophisticated than) those of ‘creation scientists’.
    — end excerpt —

  50. 250
    wilt says:

    Stefan, thanks again for your comment, this time relating to my #230 post. You wrote: “But now you’re comparing the upper limit of the IPCC range to a central estimate for a moderate warming, based on a quadratic sea level fit rather than on the actual correlation with temperature … what is the point? Just to justify a lower number?“

    I am not searching for low numbers, but I am trying to find out what projection would be fitting best to the observations from say the last 150 years.
    I have used the quadratic sea level fit following the remarks that you made earlier (#155 and #193) about the Church&White article, and the ‘sea level sensitivity’ based upon their conclusions. I then assumed a 3 degrees temperature rise by 2100. The result would then be approximately 60 cm sea level rise in total.
    Now you call the chosen value of 3 degrees ‘moderate warming’, but I may remind you that 3 degrees is well above the median value (2.6) of best estimates from all six IPCC scenario’s. In my terminology a modest warming would be 1 to 2 degrees. Using the approach described here one can only project a sea level rise of 1 meter or more during this century by supposing that the temperature increase by 2100 will be 5 or 6 degrees Celsius. One can have different opinions on whether that is a realistic temperature scenario. Such values are at the upper limit of the upper limit IPCC scenario’s.


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